Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/13/22
Area Forecast Discussion
National Weather Service Goodland KS
835 PM MST Sat Feb 12 2022
.SHORT TERM...(This evening through Monday)
Issued at 256 PM MST Sat Feb 12 2022
At the start of the short term period, the latest RAP analysis shows
the CWA having a north-northwesterly flow aloft as the CWA is
underneath the back part of a trough with a ridge over the western
CONUS. Current satellite imagery is showing some midlevel clouds
north of the CWA that are moving in a south-southeast direction. By
Saturday night, forecast guidance shows the ridge-trough pattern
continuing aloft and progressing a bit eastward. At the surface, dry
conditions are expected in the CWA with winds shifting to the
northwest after midnight as a surface low travels southeast through
central NE into eastern KS. Overnight lows for tonight look to be
in the upper teens to the lower 20s.
On Sunday, forecast models show the ridge moving eastward over the
western half of the CONUS by the evening hours allowing for a
northwesterly flow aloft throughout the day. At the surface, there
looks to be a brief weak cold front associated with the
aforementioned low passing quickly though the eastern part of the
CWA. However, a surface trough moves in over eastern CO by the
afternoon which looks to usher in a warmer air mass from the
west-southwest. There may be some elevated fire weather concerns
for areas along and west of KS-27 with a minimum RH values in the
upper teens and wind gusts above 20 kts possible. Daytime highs
on Sunday look to be in the middle 50s to the lower 60s with
overnight low temperatures in the lower to upper 20s.
For Monday, models show the flow being mostly westerly during the
day with a brief transition to northwesterly when a brief trough
passes through the flow in the evening. At the surface, dry
conditions continue for the CWA with breezy southerly winds during
the afternoon. Fire weather concerns look less likely for Monday
at this time, but this will be monitored in case they change.
Monday`s daytime highs look to be in the middle 50s while
overnight lows in the lower to middle 20s can be expected.
.LONG TERM...(Tuesday through Saturday)
Issued at 156 PM MST Sat Feb 12 2022
Main focus for this part of the forecast will be the trough moving
onto the Plains mid week.
Starting out this period will be an upper level ridge over the
forecast area. WAA on Tuesday will allow temperatures to be well
above normal.
Tuesday night a strong cold front will move through accompanying the
upper level long wave trough. Behind the front northerly winds will
increase, along with the CAA. Precipitation will also move in
behind the front as the trough axis approaches. The track of the
trough has changed very little over the last five model runs of the
GFS. The latest model run has sped up the trough arrival from the
prior four runs. The ECMWF has shifted the trough slightly further
north over the last four runs. However the trough is still well
south of the forecast area. Since the trough remains so far south,
precipitation chances have gone down. Confidence is moderate for
even an inch of snow to occur.
Regarding precipitation type, confidence is low that there will be
much rainfall before changing to snow due to the CAA Thursday.
For temperatures, highs were raised above model consensus for
Tuesday given the WAA. Highs for Wednesday and Thursday, along with
lows for Wednesday night were lowered due to the continued CAA over
the forecast area. Highs for Wednesday may not be cold enough. Wind
chills for sunrise Thursday morning could be 5 to 10 below zero.
Behind this upper level trough temperatures warm as the jet stream
shifts east of the forecast area, allowing WAA to move in.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 835 PM MST Sat Feb 12 2022
KGLD...VFR conditions are expected through the period. A west-
northwest wind around 12kts is expected through 07z, decreasing
back to speeds around 10kts from the west or northwest through
16z. From 17z-22z modest 3 hour pressure falls develop which will
back winds to the southwest with gusts around 25kts or so. After
23z west to southwest winds subside to around 10kts.
KMCK...VFR conditions are expected through the period. A west wind
around 12kts is expected through 08z, veering slightly to the
northwest and decreasing to around 10kts through 16z. After 17z
modest 3 hour pressure falls develop which will cause winds to
back to the southwest at speeds around 12-13kts with some gusts
from 20z-22z. After 23z a west to southwest wind around 10kts is
expected.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...076
LONG TERM...JTL
AVIATION...99
Area Forecast Discussion
National Weather Service Grand Rapids MI
922 PM EST Sat Feb 12 2022
LATEST UPDATE...
Update/Marine
.UPDATE...
Issued at 902 PM EST Sat Feb 12 2022
The snow showers have been tracking further inland than expected.
Part of the reason for this is that the wind was out of the west
northwest. Based on the 00z HRRR those snow showers tracking
through Kent County may reach the Lansing region. Thus...we bumped
up the POPs to account for an increased chance to see some snow
showers for inland locations.
One consideration was to add Ottawa County to the winter weather
advisory with several high res models suggesting an increased
potential for at least minor impacts in that county. However the
SPC HREF mean 12/24 hr snowfall keeps the risk for heavier snow
south and west of Holland.
&&
.DISCUSSION...(This evening through next Saturday)
Issued at 335 PM EST Sat Feb 12 2022
-Cold with Lake Effect into Monday
Will extend the Winter Weather Advisory for Allegan and Van Buren
Counties through 7 PM Sunday. Lake snows continue to hug the
shoreline tonight due to enhanced sfc convergence along a N-S
oriented sfc trough, and an upper low dropping southeast from the
Arrowhead of MN gives snow showers another boost on Sunday.
Additional localized 6" accums likely.
Some uncertainty exists as to the exact behavior of wiggly
N-S dominant snowband late tonight and early Sunday, with some
HiRes guidance pushing it mostly offshore for awhile. Also some
hints of a possible mesolow circulation developing near/south of
Holland by 12Z Sunday which could produce some intense snow rates
if it materializes.
Either way, the snow showers do return by Noon Sunday and we
could see some rather heavy bursts as the convective depth exceeds
10K ft while a strong mid level shortwave is moving through in
the afternoon. Heavier cellular snow showers could even develop
well inland from the lake on Sunday afternoon, across the area
along/south of I-96, as sfc troughing/convergence becomes oriented
in more of a west-east fashion over srn Lwr MI.
Snow showers diminishing Sunday evening behind the departing
shortwave, but another brief burst in coverage/intensity possible
on Monday as the final Clipper in departing northwest flow
pattern aloft comes through. Highest pops Monday expected to
be north of a BIV to Alma line in swly low lvl flow.
-Active Weather Wed-Thur with Hydro Concerns
Very little spread is shown in temperatures guidance on Wednesday
so it`s now looking fairly certain that highs will reach into the
mid to upper 40s. Also a strong likelihood for wind gusts of
30-40 mph out of the south-southwest as the core of a 60 kt LLJ
comes overhead. Obviously this will contribute to decent
snowmelt, especially south and east of GRR where the warmth hangs
on the longest-- through much of Wednesday night.
Ensemble support continues to grow for an inch or more of QPF from
Wed afternoon into Thursday due to strong FGEN forcing within
right entrance region of 180 kt upper lvl jet. Still unclear
though how quick the cold air rushes in from the north and
changes rain over to a mixture or snow, but it does appear likely
that the area south and east of a AZO to LAN line stands a good
chance of having much of the QPF fall as rain.
River rises will be possible over the Kalamazoo basin and eastern
reaches of the Grand as runoff from snowmelt and rainwater atop
frozen ground makes it into the system. This may lead to flooding
and maybe some break up ice jams, so if you live or work near
rivers along and south of I-96 it is time to start thinking about
a plan for monitoring the river conditions next week.
Several inches of snow remains a possibility Wed night-Thursday,
especially if a second wave on the front on Thursday impacts the
area after the cold air arrives.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 636 PM EST Sat Feb 12 2022
Lake effect band of snow showers will lead to occasional aviation
impacts through the period. IFR should be most common for KMKG
tonight as those snow showers will be most focused along the
lakeshore. Then for Sunday...the snow showers will build inland
especially towards KAZO and KBTL as the winds become onshore.
Periods of IFR look probable for those locations as well. The
lake moisture and associated clouds/snow showers will continue to
expand further inland. MVFR impacts are expected to prevail...but
will need to monitor for possible brief IFR even for KJXN and
KLAN during the day.
&&
.MARINE...
Issued at 902 PM EST Sat Feb 12 2022
The small craft advisory was allowed to expire earlier. Overall
the pressure gradient weakens slightly overnight so the wind is
not expected to increase. Currently all sites are below 10 knots
so no headlines are anticipated at this time.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Winter Weather Advisory until 7 PM EST Sunday for MIZ064-071.
LM...None.
&&
$$
UPDATE...MJS
DISCUSSION...Meade
AVIATION...MJS
MARINE...MJS
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
813 PM CST Sat Feb 12 2022
.UPDATE...
Updated for evening discussion.
&&
.DISCUSSION...
No major updates needed for this evening, but will mention that
our ragged band of precipitation has been persistent this evening.
The combination of some mid- and upper-level lift and moistening
ahead of the approaching shortwave trough has been enough to
generate snow aloft all afternoon. Most has been melting and
evaporating, but some brief periods of light snow with visibility
down to about 2.5 miles were reported with the band as it moved
through the Greenville area earlier. With temperatures falling
overnight and the forcing encountering a slightly more humid air
mass in the south, the HRRR has been especially persistent with
depicting a second burst of activity in the Pine Belt of southeast
MS late tonight and early Sunday morning. There is even support
among the global guidance (GFS, ECMWF, and CMC) for some light
precip as the tip of the shortwave swings through overnight.
Therefore the POPs were bumped up slightly across southeastern
portions of our forecast area to include a mention of "Chance"
rain/snow/sleet from after Midnight tonight through around 6 a.m.
The temperature profile aloft supports snow falling as long as the
rates can overcome the dry sub-cloud layer. No accumulations are
expected, and no impacts are expected, but a pleasant burst of
flurries or light snow may surprise some in the early morning
hours. Continued to trend dew points lower and winds a little
higher in the wake of the front tomorrow. Exceptionally dry air in
the lower levels will help surface relative humidity drop to
around 20 percent or lower with daytime mixing in the post-frontal
air mass. This will drive another day of "Elevated" fire weather
concerns across the area. Burning should be avoided and caution
exercised with any activities that create flames or sparks near
vegetation. /NF/
Prior discussion below:
Through Sunday:
A disjointed cold front continues to gradually work its way
across the region this afternoon. The theta-e gradient associated
with the front this afternoon continues to lag well behind the
pressure trough from just north of Alexandria to Vicksburg to the
Golden Triangle. A narrow band of postfrontal showers was just
entering the upper Delta and southeast AR as of 2 PM. With surface
temps below 40 reaching a line from around Fountain Hill AR to
Cleveland to Oxford, light snow is beginning to mix in with the
rain mainly north of this line - especially in areas where temps
were getting into the middle 30s and below. As this band of precip
continues eastward and encounters considerable dry air it is
expected to greatly diminish into this evening, though precip on
the back edge of it may still briefly mix with or change over to
light snow. Heading through the evening guidance has hinted at the
potential for some redevelopment of light precip overnight across
south MS. With low rates, above freezing air temps, and warm
ground conditions, no issues are anticipated. Again, it is likely
that most areas won`t see even light snow. The PoP and Wx forecast
for tonight reflect only spotty, isolated precip.
The greater focus for impacts in the near term is continued elevated
fire danger. Even today in areas ahead of the front, RHs have fallen
to near 30% in spots and with gusty northerly winds and antecedent
dry conditions, we`re still seeing limited fire danger in southeast
MS. For Sunday, with the reinforcing dry airmass behind the front,
widespread minimum RHs in the upper teens to 20s are expected with
mixing resulting in breezy conditions at times. Today`s front will
provide little to no relief in the way of precipitation, and given
the recent fire activity we`ve seen and expected low humidity, we
have opted to increase the fire danger in the HWO/graphics to the
elevated category again for tomorrow. Otherwise, weather conditions
will be clear as surface ridging builds across the center of the
CONUS. /DL/
Sunday night through Friday night:
The primary weather concern over the forecast area going through
early week will continue to be with fire danger. After a cold
Sunday night, the trough responsible for the cooler weather will
shift quickly east as impressive Pacific jet dynamics translate
into a strong western CONUS trough. This transition will result in
a warming trend with strong daytime mixing supportive of low
afternoon RH and gusty surface winds. As of now, we are carrying
the elevated threat for fire danger through Monday, but this could
very well be extended into Tuesday given that gradient return
flow winds will likely be on the increase before moisture levels
can respond. Going into Wednesday, the surface wind will be
stronger, but we should have steadily increasing boundary layer
dewpoints by then helping to mitigate fire danger.
With the approaching trough Wednesday night and Thursday, the
concern quickly shifts to severe weather and perhaps even heavy
rainfall for the lower MS Valley region. As described in the
previous discussion, there are still some uncertain points in the
global model guidance regarding the primary shortwave trough
timing and strength. In the very general sense, we expect
thunderstorms, and plenty of forcing and wind shear for an
organized severe threat, but with model timing and wave intensity
in flux, confidence is not all that high with how this is going
to play out. With all that said, the broadbrushed slight severe
risk denoted in the current HWO graphic for the entire area
Thursday remains valid with little confidence in trying to get
more specific at this point.
Following the initial cold frontal passage, some guidance are
hinting at maintaining a lingering baroclinic zone with
subsequent shortwave energy possibly bringing an additional round
of rainfall, but will continue to follow the dry/cool consensus
output for now to finish the week. /EC/
&&
.AVIATION...
00Z TAF discussion:
Northerly winds will generally continue through the forecast
period at all sites, with winds turning out of the west at KGLH by
18Z Sunday. Some gusts will be possible to start, but expect winds
to decrease and become less gusty by 06Z Sunday. A line of light
rain or snow showers will move across the region tonight, bringing
possible brief periods of reduced visibility to the MVFR range.
Confidence in this decreases farther east, so has been left out of
the TAFs except at KGLH and KGWO at this current time. /NF/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 26 52 29 64 / 24 0 0 0
Meridian 28 51 28 63 / 21 0 0 0
Vicksburg 27 53 30 65 / 19 0 0 0
Hattiesburg 33 54 29 64 / 28 10 0 0
Natchez 28 53 31 65 / 24 0 1 0
Greenville 26 53 29 64 / 14 0 0 0
Greenwood 24 50 28 62 / 14 0 0 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
NF/DL/EC
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
826 PM CST Sat Feb 12 2022
.UPDATE...
Issued at 826 PM CST Sat Feb 12 2022
Couple of minor adjustments made to going forecast this evening,
including raising min temps a bit across the west where cloud
cover looks to be a little more prevalent than earlier, and also
to slow the arrival of light snow toward morning across the far
west/southwest counties slightly.
Evening surface analysis depicts weak high pressure across
downstate IL, with modest west-northwest low level winds across
the forecast area. GOES IR satellite depicts considerable cloud
cover across eastern IA and much of northern IL, which model
guidance has struggled with today (especially with shallow, thin
stratocu earlier). With window for clearing skies decreasing have
raised min temps a bit especially across the west where temps
lower than 5 above are looking less likely, in addition to
increasing sky cover.
Turning attention farther to the northwest this evening, a fairly
vigorous mid-level short wave trough was noted in GOES vapor
imagery digging south-southeast from Manitoba into the upper
Midwest. Surface low pressure currently centered along the SD/NE
just north of Valentine (KVTN) is progged to track southeast
through the Missouri and lower Ohio valleys through Sunday,
beneath the nose/left exit region of a 125 kt upper level jet
streak. Low level warm advection was already noted southeast of
the low across the mid-Missouri Valley in the 925-850 mb layer,
which will tighten the low level baroclinic zone and is progged to
result in increasing frontogenetic forcing from central/eastern IA
into central IL into Sunday as the system tracks southeast. Model
cross sections indicate the strongest f-gen induced ageostrophic
ascent and juxtaposition with the DGZ will lay out from eastern IA
into central IL - where guidance nicely depicts the QPF axis. For
the WFO LOT cwa, our southwest counties will be on the
northeastern periphery of this band of light snow, with some minor
accums generally under an inch expected Sunday morning. Going
forecast handles this placement very well, though did delay some
of the higher chance pops until just after 12Z per latest model
trends. Flurries will likely extend farther northeast/east across
the cwa during the morning, though no accumulation is expected
northeast of roughly a KVYS-KLAF line. Otherwise, no changes made
to the going forecast.
Updated forecast products already available.
Ratzer
&&
.SHORT TERM...
Issued at 220 PM CST Sat Feb 12 2022
Through Sunday...
Short term forecast interests are 1.) cloud and temperature
trends this evening, and then 2.) a quick-moving clipper system on
Sunday morning, bringing with it the chance of flurries areawide
and potential for light accumulating snow south of a LaSalle-Peru
to Watseka line.
Pesky stratocumulus has stood its ground (or sky we should say)
this afternoon within continued, albeit weakening, 925 mb cold air
advection. Much of this is closed celled across the area as of
2 PM, pointing toward any clearing needing advection. Westerly
winds around 15 kt at cloud level will help to clear some if not
all of north central and far northern Illinois before mid cloud
moves in late this evening, but confidence diminishes quickly for
locations east of there. It`s possible any clearing is very
limited from Chicago southward and especially for northwest
Indiana. If that`s the case, temperatures will only drop a few
degrees in total tonight. For the western CWA, where confidence is
a little higher in a period of evening clearing in-sync with the
surface ridge axis passage, forecast single digit lows are
reasonable. MOS guidance even has lows of 5 or below for some of
the sites in the west, but that seems a smidge too cold.
Temperatures will probably inch up a few degrees overnight once
mid cloud moves in from the northwest.
The clipper system -- that is a low amplitude, progressive, wave
from the northwest -- is diving southeastward into western
Minnesota this afternoon. This is within the left exit region of
a 125 kt equatorward pointing upper jet and a notable potential
vorticity (PV) anomaly. A responsive tightening of the baroclinic
zone in the 850-700 mb layer will occur to the south of the mid-
level wave center and is where the best chance for a corridor of
frontogenesis-forced snow is. In the past 12-18 hours, this has
trended a wee bit northward in guidance solutions. This favored
axis of light accumulation is still just to the southwest of the
forecast area, though with the northward nudge in guidance this
has resulted in an increase in the chance for snow to graze the
southwest CWA. This again is mainly south of a LaSalle-Peru to
Watseka line, where a 2-4 hour period of light snow may occur. The
maximum lift is forecast in the -16C to -22C layer, a little
colder than ideal. Envision an upper case scenario of up to an
inch in places like Pontiac and Gibson City, with lowest case
being no snow accumulation at all.
Further to the north on Sunday morning, there is much less
forcing, but with the cold air mass it should not take much lift
to result in saturation of a sufficient depth for at least spotty
flurries. A few guidance solutions even show splotchy QPF Sunday
morning. While that looks overdone, because of the cold, can`t
rule out a little bit sticking here and there.
Otherwise for Sunday, the clipper passage will briefly re-enhance
the low-level cold advection, and as such clouds are forecast to
stick around into the afternoon. Some clearing is likely to work
into the far north, but how quickly that spreads south is
uncertain. Highs look to be around 20 (over 10 degrees below
normal) with only a small diurnal climb. Also with the uptick in
low-level cold advection, lake effect snow showers are likely to
creep back up in coverage into far northwest Indiana late Sunday
morning into afternoon. Forecast lake-induced equilibrium levels
on the RAP and HRRR extend up to about 9,000 ft, so not shabby at
all. It just looks like the window of time may be somewhat short
and low-level convergence looks like it will remain over the
eastern half of the lake. Plus, drier air is working in above
5,000 ft gradually through the afternoon. Some light accumulation
of mainly an inch or less into Porter County in our forecast area
is what we presently have forecast for this.
MTF
&&
.LONG TERM...
Issued at 210 PM CST Sat Feb 12 2022
Sunday Night through Saturday...
Forecast concerns include a chance of light snow early Monday
morning with a weak clipper system and then a storm system for
Wednesday into Thursday that will affect the region.
A weak clipper system will move across the area early Monday
morning bringing with it a chance for light snow or flurries. The
models have always shown limited moisture with this system, which
is still the case. Though there still is a chance for a dusting of
snow across mainly the northern half of the area, centered in the
09z-12z time period. Added slight chance pops to the forecast for
this potential but no qpf or snow for now. Confidence remains low
for how much, if any, accumulation may materialize and its
possible that most of what falls will be more flurries. Low temps
will likely occur in the evening when some clearing is expected,
then clouds will quickly increase ahead of this clipper and temps
are likely to hold steady in the low teens through daybreak Monday
morning. Dry weather is then expected Monday afternoon through
Wednesday morning with a slow warming trend. High temps look to
reach the lower 30s Monday and then possibly make a run into the
lower 40s for Tuesday, perhaps holding in the 30s over the snow
pack areas across the central/southern cwa.
Still too early for specifics regarding the storm system for
Wednesday/Thursday next week. The same concerns of the past few
days remain, potential for heavy rain Wednesday evening/night,
changing over to a wintry mix/freezing rain and then snow as
precip ends on Thursday. Strong southerly winds on Wednesday with
the potential for strong northerly winds on Thursday.
The main change with the 12z operational runs is a continued jog
south and perhaps an overall faster progression. The lead wave
still allows for a period of moderate to perhaps heavy rain,
mainly across the southern half or southern third of the area
Wednesday evening. But this then pushes the cold front through
faster. Even more uncertain is the second wave and how far north
it moves and if it stays south of the area. A transition from rain
to a wintry mix/freezing rain then snow still looks reasonable
for now, for Wednesday night. And then the second wave could be
quite a bit of snow, if it were to reach this far north. Still a
lot of uncertainty from this distance and no changes to the
blended guidance, which based on the latest model guidance has
shifted considerably colder for Wednesday night into Thursday and
shifted drier Thursday afternoon into Thursday evening.
Still too early to include any sleet/freezing rain mention in the
grids/zone forecasts, especially since it could be fairly short
in duration and timing/location remain uncertain. However, from an
areawide perspective, confidence is increasing enough to include
limited ice mention in the HWO for freezing rain and will
maintain the limited flooding mention, though as current trends
show, this may be centered mainly on the southern third of the
cwa. There would also be some potential for some of the rain that
falls to freeze in place, limiting runoff into rivers and streams,
if colder temperatures do indeed spread into the area faster.
Low temps by Friday morning could be back into the low single
digits, possibly low single digits below zero in the favored cold
spots. Temps then moderate Friday into Saturday. cms
&&
.AVIATION...
For the 00Z TAFs...
Quiet and mainly VFR conditions are expected through the TAF
period. Some lingering high end MVFR cigs 2900-3000ft eventually
scatter out over the next hour or two. There may even be a few
snowflakes at times, but not enough for a formal TAF mention.
Winds remain westerly overnight generally under 10kts then
trending northwesterly during the daylight hours. Winds ease again
Sunday evening becoming very light and turning west and then
southwest.
An area of light snow will swing across portions of Illinois
Sunday AM. This is expected to remain southwest of the Chicago
area terminals. It is possible it brushes RFD so have held onto a
brief mention of light snow there along with any associated high
end MVFR cigs. The rest of the TAF sites could see occasional
non-impactful flurries during that time.
Petr
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...Small Craft Advisory...IN nearshore waters until 9 PM Saturday.
&&
$$
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Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
513 PM CST Sat Feb 12 2022
.UPDATE...
Issued at 508 PM CST Sat Feb 12 2022
Updated for the 00z aviation discussion below.
&&
.DISCUSSION...(This evening through Saturday)
Issued at 246 PM CST Sat Feb 12 2022
Key messages:
- Dangerous cold again tonight, with wind chill values between 15
and 30 degrees below zero.
- Up to an inch of snow possible around the MN/WI border Sunday
evening
The arrival of clouds earlier than forecast has really tapped the
breaks on any appreciable warmup today, with temps this afternoon
struggling to sneak above zero as a result. This cloud cover is the
result of WAA out ahead of a surface low over southeast MT that will
quickly travel to northern Missouri tonight. Some light snow is
still possible with this WAA, but we`ve been watching the HRRR
slowly back away from producing much snow with this wave and there
are couple of culprits. One is the forcing is quite weak given how
far southwest the surface low will be from us. The other problem is
when looking at forecasting soundings, we`re cold enough to where
the entire atmosphere is colder than the DGZ, so you tend to get poor
snow crystal generation. Have left PoPs, mostly unchanged for
tonight, with a quick hit of likelies dropping through western MN,
but any amounts will be under a half inch.
Given how cold it stayed this afternoon and the fact that we`ll see
yet another high moving in late tonight, did nudge forecast lows for
tonight down some, but we could go lower, especially in central MN
depending how quickly we can move clouds out of the area behind this
first clipper. Did issue a wind chill advisory from western into
central MN after collaboration with neighbors, as hazardous wind
chills will be easy to achieve with air temperatures getting down to
near -20F.
Sunday will be similar to today with high pressure overhead
resulting in a cold start, with a clipper bringing a chance for snow
in the evening. The colder trend continues to the highs for Sunday,
which now look to stay in the single digits away from the Buffalo
ridge. The clipper for Sunday evening will be farther east than the
one for this evening, but the surface low will be filling as it
moves across MN, so a diminishing trend is expected with the band of
snow that falls to the cold side of the low track. Did bump up PoPs
toward the ConShort grids, to be bring in a band of categorical
pops. Soundings show a warmer atmospheric profile being in place for
this clipper, with large portions of the profile residing in the
DGZ, so we should see more efficient snow production with this wave.
With that said, moisture is very limited, so we`re talking an inch
of snow at best along the MN/WI border.
Behind this clipper is yet another high pressure, which means our
warmup for next week gets delayed to more Monday night, with highs
Monday again nudged down, with those now forecast to remain in the
teens. Tuesday, a surface low will track across Canada. This will
drag a cold front across our area Tuesday night. Ahead of this cold
front, southeast winds will kick up for Tuesday, with highs taking a
quick jump up into the upper 20s/mid 30s, with 40s possible in SW
MN. Wednesday will be yet another CAA day, with highs happening in
the early morning hours and temperatures slowly falling trough the
day. The southern stream look to interact with the baroclinic zone
with this front Wednesday into Thursday, but the resultant
precipitation swath with that will remain well off to our southeast.
Instead, it`s another quick blast of cold air to end the week. We
continue to see a downward trend with highs for Thursday, with those
looking to remain largely in the single digits once again.
This cool down on Thursday will be followed by another quick warm up
as yet another clipper slides off to our north Friday night. This
clipper will send another strong cold front across the upper MS
Valley next weekend. What`s interesting with this front though is
that it will likely be running into building heights across the
CONUS. This may allow the baroclinic zone with the front to get hung
up over/near our area which may finally allow for some better precip
chances into the our region as we get into the last week of
February.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 508 PM CST Sat Feb 12 2022
Snow chances continue to look slim for this evening. Kept in some
-SN BR for KAXN and KRWF, but other locales will remain dry. Some
MVFR conditions are possible throughout the overnight before
returning to VFR by tomorrow morning. Another clipper system will
move across the region late tomorrow, bringing another chance of some
light snow. This system looks a bit more promising, but the timing
for most sites lies just beyond the end of the forecast period. Winds
remain light throughout with a southerly shift tomorrow afternoon.
KMSP...As mentioned above, went ahead an put in a PROB30 for some
snow tomorrow evening after 00z. Otherwise, no additional concerns.
/OUTLOOK FOR KMSP/
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Wind Chill Advisory from midnight tonight to 9 AM CST Sunday for
Benton-Chippewa-Douglas-Kanabec-Lac Qui Parle-Mille Lacs-
Morrison-Pope-Stearns-Stevens-Swift-Todd.
WI...None.
&&
$$
UPDATE...
DISCUSSION...MPG
AVIATION...Dye
Area Forecast Discussion
National Weather Service Marquette MI
701 PM EST Sat Feb 12 2022
.SHORT TERM...(Through this evening)
Issued at 147 PM EST SAT FEB 12 2022
As a sfc ridge of high pressure continues to track into the region,
winds will continue to decrease and back more to the
west...eventually going calm by tonight. As gradient flow decreases,
LES will also continue to wind down and remain closer to the
shoreline into this evening. With arctic air overhead, the DGZ
remains near the sfc which has led to reductions in vsbys due to
smaller snowflake sizes, with amts remaining light as well. LES
will continue to shift north along the wern UP through this
afternoon and evening, and GOES shows this pattern well, though
shouldn`t expect much more than a half an inch or so. Highs
through the rest of the day will remain in the single digits
across most of the UP, with some low double digits across the
south-central.
.LONG TERM...(Sunday night through Saturday)
Issued at 321 PM EST SAT FEB 12 2022
Primary concerns tonight will be the continued very cold
temperatures blanketing the U.P. and the mesolows that will
develop over Lake Superior and threaten the land.
Starting off this discussion with those mesolows, hi-res guidance
hones in on two main lows that develop tonight: one in the east
and one in the west. The one in the west is forecast to develop
within LSZ-263, then riding along/near the LSZ-162 border as it
approaches the shorelines of Ontonagon and Gogebic counties. The
one in the east develops within LSZ-266, spinning just
off/alongshore of Alger County. Earlier runs of the HRRR, such as
the 15z run, showed a smaller, secondary mesolow developing within
the eastern portion of LSZ-265, which seemed reasonable that a
mesolow could develop along the edge of the ice there. But, later
runs of the HRRR seem to be not as favored for this secondary
mesolow, backing off a bit and showing that more robust one in
266. Putting all of the pieces together, the forecast for tonight
into early tomorrow is some moderate snow can be expected in the
west with that Ontonagon/Gogebic mesolow; moderate snow can be
expected in the east with that Alger mesolow; and should a
smaller, weaker mesolow develop in 265, could see some moderate
snow scrapping along the Marquette County shoreline. All of these
though look to keep the heavier snow offshore, but **very short-
term watching is warranted should any of these rotate the heavier
bands onshore.**
Temperatures tonight are again expected to dip well below normal,
with sub-zero temps just about everywhere. Negative teens will
dominate the interior, with the mitigating factors against a wind
chill advisory being the lack of meaningful winds and incoming
mid-to upper-level cloud cover as an upper trough passes overhead.
Which leads into the next portion of this discussion: the next
synoptic disturbance will be an approaching weaker shortwave with
an associated surface clipper scooting past Sunday night. Models
have been cutting back on PoPs, and have this reflected in this
latest forecast. There are still chances though for some snow to
develop and spread across portions of the U.P. Sunday night into
early Monday, but amounts, if any, will be low. Reinforcing cold
air will ensure at least some LES on the backside of this grazing
clipper. There looks to be a bit of a reprieve late Monday into
early Tuesday for many, but then the next disturbance brings
widerspread PoPs late Tuesday into Wednesday. This is associated
with a low traversing across northern Ontario, allowing for some
WAA to return to Upper Michigan in the middle of the week. Once
this low passes though, expect the rather cold temps to return,
along with accompanying LES - just in time for area outdoor winter
happenings and therefore an influx of visitors. The pattern
currently looks to remain chilly, progressive, and unsettled
coinciding with said activities.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 700 PM EST SAT FEB 12 2022
Other than some lingering MVFR at KSAW for the next few hours,
remaining TAF sites are currently at VFR levels. Nonetheless, will
carry mention of light snow showers and MVFR/IFR CIGS at IWD tonight
through tomorrow morning as hi-res guidance continues to pick up on
a mesolow over western Lake Superior. Elsewhere, expect some
fluctuation between VFR/MVFR at KCMX/KSAW. Meanwhile, winds will
generally be light and variable before becoming primarily
northwesterly.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 426 PM EST SAT FEB 12 2022
Outside of mesolows that develop tonight into early tomorrow,
winds will generally remain less than 25 knots into early next
week. Stronger winds re-emerge late Tuesday through much of the
upcoming week, with gusty Srly winds looking to approach low-end
gales to start, becoming Wrly on Wednesday, then Nrly on Thursday,
with the winds finally subsiding a bit at the end of next week.
There is a potential for some moderate to perhaps heavy freezing
spray during this time period notably from late Wednesday into
early Friday as a colder airmass returns behind a brief period of
warmer air advecting in.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JAW
LONG TERM...lg
AVIATION...TDUD
MARINE...lg
Area Forecast Discussion
National Weather Service Mount Holly NJ
952 PM EST Sat Feb 12 2022
.SYNOPSIS...
A cold front will continue moving offshore tonight then low pressure
will develop along it on Sunday and push well out to sea. Strong
high pressure will build across the region through Tuesday. As the
high moves offshore into Wednesday, strong southerly flow will
develop through Thursday. Low pressure will pass from the Ohio
Valley Thursday and progress quickly across the Saint Lawrence
Valley Thursday night. This will push a strong cold front across the
area Thursday night then high pressure will return for Friday and
Saturday.
&&
.NEAR TERM /THROUGH SUNDAY/...
Changes with the late evening update: delayed the PoPs
increasing over the near coastal areas as it appears that the
precipitation shield may be a bit slower to spread eastward.
This consequently resulted into a minor adjustment downward for
snow amounts for portions of central Delmarva and the NJ shore.
Precipitation is starting to reach the ground in the DC metro
area, and the 00Z soundings around the region suggest that
moisture advection is underway for the boundary layer. The 00Z
soundings especially over OH and Central NY depict the upper
level jet strengthening (as compared to 12 hours ago). In
response, expect the surface low over eastern NC (along the cold
front) to deepen and intensify over the next 12 hours.
The precipitation associated with the low should spread
northeastward and into our region after midnight. Boundary layer
temperatures may be warm enough at the onset to result in a
little rain, but the precipitation should change to a rain snow
mix and then all snow before sunrise. Many of the high res
models, especially the HRRR, depict the precipitation being much
slower to progress eastward towards the coast overnight. I`m not
ready to fully buy in to the HRRR solution, especially given
that the larger scale models depict an upper level jetlet
developing just SE of the main jet after 06Z. This would suggest
that the precipitation would accelerate southeastward with this
development. Thus, I slightly delayed the progression eastward
of the PoPs, but still not nearly as slow as what the HRRR
depicts.
The snow is expected to be enhanced along the Interstate 95 Corridor
and vicinity very late tonight by the lift under the rear
entrance region of the upper level jet. This band should drift
eastward on Sunday morning and off the coast during the
afternoon.
This will likely be another case when the Poconos, Berks County, the
Lehigh Valley and northwestern New Jersey get less snow than areas
to the southeast. Amounts up there should be less than 2 inches. We
are anticipating 1 to 3 inches along and near the Interstate 95
Corridor. As a result, those areas are under a Winter Weather
Advisory. Snowfall totals should decrease for Sussex County,
Delaware and Cape May County, New Jersey due to the later
arrival, slightly warmer temperatures, and a possible mix with
rain at times. Around an inch or less is forecast there.
While the snow is expected to end from west to east on Sunday, the
sky should remain mostly cloudy for the balance of the day.
Lows are forecast to range mainly from the middle 20s to the lower
30s tonight. Highs on Sunday will be considerably colder than those
of today. Highs are expected to be mostly in the upper 20s to the
middle 30s.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
Overall quiet but cold weather is expected through Tuesday. The
trough axis responsible for the snow on Sunday will be moving
offshore Sunday night. A few additional shortwaves will pass over
the region into Monday through, which will bring a few periods of
clouds and the potential for some flurries. Ridging will build in
the wake of the trough through Tuesday. Strong cold advection will
be continuing Sunday night and temperatures will fall into the 10s.
This combined with sustained winds around 10 mph will result in
minimum wind chills mostly in the single digits above zero (as low
as -10 in the southern Poconos). The cold will continue on Monday
with highs 10-15 degrees below normal and daytime wind chills mostly
in the 10s. Monday night will be the coldest of the week with lows
likely a few degrees lower than Sunday night thanks to improved
radiational cooling conditions. The strong surface high will pass
across the region on Tuesday and the airmass will begin to modify.
Thus temperatures will be a bit closer to normal with highs mostly
in the mid to upper 30s.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A mid-level ridge axis will pass offshore of the East Coast early
Wednesday pushing the strong and cold early week surface high
pressure offshore. As a strong frontal system pushes slowly across
the Great Lakes region Wednesday through Thursday, a strengthening
southerly gradient flow will develop across much of the east and
southeastern CONUS resulting in a rather robust warm air advection
regime. This will push temperatures to well above normal levels for
Wednesday and especially Thursday. High temperatures Wednesday will
be in the 50s (10 degrees above normal) in most locations and in the
60s (about 20 degrees above normal) on Thursday. A few record highs
could be challenged on Thursday. With lack of any moisture or
forcing, Wednesday should be dry with clouds gradually increasing
throughout the day and a southerly wind around 10-15 mph.
On Thursday, low pressure will pass from the Ohio Valley and
progress quickly across the Saint Lawrence Valley through Thursday
night while intensifying. Guidance is in good agreement that the
associated cold front will push across the area sometime Thursday
night. This system will bring widespread rain showers and perhaps a
few thunderstorms. With PWats climbing to near 1.5", heavy rain will
be a threat with any convectively enhanced elements of the
precipitation (or any storms). However, this system will be quite
progressive and there won`t be any snowpack on the ground in most
areas, so I don`t think we will see any significant or widespread
flooding concerns. We`ll have to keep an eye on the potential for a
marginal severe weather threat will this system as well. As it
currently stands, the instability will be extremely limited, but
just something to monitor in the coming days. The main timeframe of
precipitation currently appears to be mostly during the Thursday
afternoon and evening timeframe, but there is still plenty of time
for this to wiggle around a bit. In any case, the precip should be
over with the front offshore by daybreak Friday.
Southerly gradient winds will increase during the daytime Thursday
before the cold front arrives with sustained values of 15-25 mph and
gusts of 30-40 mph possible, especially near the coasts. Breezy
conditions will continue behind the front into Friday as well, but
the strongest winds look to be mostly ahead of the front in the warm
sector. Ridging and surface high pressure will return for Friday and
Saturday with temperatures returning to seasonable values.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY and surrounding areas.
Tonight...VFR through 06z, then deteriorating conditions as
precipitation moves into the region. Precip will likely start as
rain/snow mix, particularly from the I-95 corridor east. A
transition to all snow will occur for all areas by 10Z. Northwest
wind 5 to 10 knots. High confidence in overall pattern, medium
confidence in precipitation start time.
Sunday...IFR conditions in snow in the morning, improving to MVFR in
the afternoon as the snow ends from west to east. North to northwest
wind 5 to 10 knots. Medium confidence.
Outlook...
Sunday night...Any lingering restrictions will dissipate and improve
quickly to VFR overnight. Winds northerly around 5-10 kts. High
confidence.
Monday...VFR. Northwesterly winds 10-15 kts with some gusts to
around 20 kts possible. Winds becoming westerly 5 kts or less after
00Z. High confidence.
Tuesday...VFR. Westerly winds 5-10 kts during the day will shift
south to southeasterly 5 kts or less after 00Z. High confidence.
Wednesday through Wednesday night...VFR with increasing cloud cover.
Southerly winds 10-15 kts with some gusts to around 20 kts possible.
LLWS possible at night. High confidence.
Thursday...Initially VFR with sub-VFR restrictions likely developing
near or after 18Z. Moderate to heavy rain showers. Southerly winds
10-20 kts with gusts around 30 kts possible. Winds will shift to the
northwest behind a cold front 10-15 kts with gusts up to 25 kts
before daybreak Friday. LLWS possible through Thursday evening.
Moderate confidence.
&&
.MARINE...
A northwest wind 10 to 15 knots is forecast to become north 15 to 20
knots for late tonight and Sunday. We are anticipating some gusts in
excess of 25 knots from late tonight into Sunday morning on the
coastal waters off Delaware. As a result, that area is under a Small
Craft Advisory from 1:00 AM until 10:00 AM Sunday.
Waves on our ocean waters should favor the 2 to 4 foot range. Waves
on Delaware Bay are expected to be 2 feet or less.
Outlook...
Sunday night through Monday...Advisory conditions possible. North to
northwesterly winds 15-20 kts. Gusts to 25 kts possible. Seas 2-4
feet.
Monday night through Tuesday night...Sub-advisory conditions
expected. Westerly winds 10-15 kts will shift to the southeast
Tuesday night. Seas 2-3 feet.
Wednesday through Wednesday night...Advisory conditions possibly
developing. Southerly winds 15-20 kts with gusts up to 25 kts
possible. Seas 2-4 feet, possibly near 5 feet Wednesday night.
Thursday...Advisory conditions likely with gale force winds/gusts
possible. Southerly winds 20-30+ kts. Seas increasing to 5-8 feet,
possibly over 10 feet Thursday night. Moderate to heavy rain showers
developing late.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Winter Weather Advisory from 1 AM to 1 PM EST Sunday for
PAZ070-071-101-102-104-106.
NJ...Winter Weather Advisory from 1 AM to 4 PM EST Sunday for
NJZ013-014-016>022-026-027.
Winter Weather Advisory from 1 AM to 1 PM EST Sunday for
NJZ012-015.
DE...Winter Weather Advisory from 1 AM to 4 PM EST Sunday for
DEZ001-002.
MD...Winter Weather Advisory from 1 AM to 4 PM EST Sunday for
MDZ012-015-019-020.
MARINE...Small Craft Advisory from 1 AM to 10 AM EST Sunday for ANZ454-
455.
&&
$$
Synopsis...Staarmann
Near Term...Iovino/Johnson
Short Term...Staarmann
Long Term...Staarmann
Aviation...AKL/Iovino/Staarmann
Marine...Iovino/Staarmann